#include <iostream>
#include <vector>
#include <assert.h>
#include <algorithm>
using namespace std;
#define int int64_t
vector<int> compress(vector<int> a) {
vector<pair<int, int>> cool;
for (int i = 0; i<a.size(); i++) {
cool.push_back({a[i], i});
}
sort(cool.begin(), cool.end());
int last = INT64_MIN;
int counter = -1;
for (int i = 0; i<a.size(); i++) {
if (last != cool[i].first) counter++;
last = cool[i].first;
cool[i].first = counter;
swap(cool[i].first, cool[i].second);
}
sort(cool.begin(), cool.end());
vector<int> res;
for (auto i: cool) {
res.push_back(i.second);
}
return res;
}
vector<int> tree;
void update(int v, int rl, int rr, int pos, int x) {
if (rl == rr) {
tree[v] = x;
return;
}
int rm = (rl + rr) / 2;
if (pos <= rm) update(v*2, rl, rm, pos, x);
else update(v*2+1, rm+1, rr, pos, x);
tree[v] = max(tree[v*2], tree[v*2+1]);
}
int querry(int v, int rl, int rr, int ql, int qr) {
if (ql > qr) return 0;
if (rl == ql && rr == qr) return tree[v];
int rm = (rl + rr) / 2;
return max(querry(v*2, rl, rm, ql, min(qr, rm)), querry(v*2+1, rm+1, rr, max(ql, rm+1), qr));
}
vector<int> lisfast(vector<int> a) {
tree.assign(a.size()*4, 0);
a = compress(a);
vector<int> dp(a.size());
dp[0] = 1;
update(1, 0, a.size()-1, a[0], 1);
for (int i = 1; i<a.size(); i++) {
dp[i] = max(1 + querry(1, 0, a.size()-1, 0, a[i]-1), dp[i-1]);
update(1, 0, a.size()-1, a[i], dp[i]);
}
return dp;
}
vector<int> ldsfast(vector<int> a) {
tree.assign(a.size()*4, 0);
a = compress(a);
vector<int> dp(a.size());
dp[0] = 1;
update(1, 0, a.size()-1, a[0], 1);
for (int i = 1; i<a.size(); i++) {
dp[i] = max(1 + querry(1, 0, a.size()-1, a[i]+1, a.size()-1), dp[i-1]);
update(1, 0, a.size()-1, a[i], dp[i]);
}
return dp;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, x; cin >> n >> x;
assert(x == 1e9);
vector<int> a(n);
for (int i = 0; i<n; i++) {
cin >> a[i];
}
vector<int> fromBeginning = lisfast(a);
reverse(a.begin(), a.end());
vector<int> fromEnd = ldsfast(a);
reverse(fromEnd.begin(), fromEnd.end());
// for (int i: fromBeginning) cout << i << " ";
// cout << "\n";
// for (int i: fromEnd) cout << i << " ";
// cout << "\n";
int res = 0;
for (int i = 0; i<n-1; i++) {
if (fromBeginning[i] + fromEnd[i+1] > res) res = fromBeginning[i] + fromEnd[i];
}
if (fromBeginning[n-1] > res) res = fromBeginning[n-1];
cout << res << "\n";
return 0;
}
Compilation message
glo.cpp: In function 'std::vector<long int> compress(std::vector<long int>)':
glo.cpp:17:22: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
17 | for (int i = 0; i<a.size(); i++) {
| ~^~~~~~~~~
glo.cpp:26:22: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
26 | for (int i = 0; i<a.size(); i++) {
| ~^~~~~~~~~
glo.cpp: In function 'std::vector<long int> lisfast(std::vector<long int>)':
glo.cpp:80:22: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
80 | for (int i = 1; i<a.size(); i++) {
| ~^~~~~~~~~
glo.cpp: In function 'std::vector<long int> ldsfast(std::vector<long int>)':
glo.cpp:101:22: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
101 | for (int i = 1; i<a.size(); i++) {
| ~^~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
155 ms |
10200 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
460 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |